Single-particle Excitation Spectra of C$_{60}$ Molecules and Monolayers

TL;DR

This study uses quantum Monte Carlo and cluster perturbation theory to analyze the single-particle excitation spectra of C$_{60}$ molecules and monolayers, aligning theoretical results with experimental data to understand their electronic properties.

Contribution

It demonstrates that a simple Hubbard model with intermediate coupling accurately describes the electronic spectra of C$_{60}$ systems, supported by comparison with experimental data.

Findings

Estimated intermolecular hopping integrals and molecular orientation angles.

Agreement with experimental photoemission and diffraction data.

Validation of the Hubbard model with U=4t for C$_{60}$ properties.

Abstract

In this paper we present calculations of single-particle excitation spectra of neutral and three-electron-doped Hubbard C$_{60}$ molecules and monolayers from large-scale quantum Monte Carlo simulations and cluster perturbation theory. By a comparison to experimental photoemission, inverse photoemission, and angle-resolved photoemission data, we estimate the intermolecular hopping integrals and the C$_{60}$ molecular orientation angle, finding agreement with recent X-ray photoelectron diffraction (XPD) experiments. Our results demonstrate that a simple effective Hubbard model, with intermediate coupling, $U=4t$, provides a reasonable basis for modeling the properties of C$_{60}$ compounds.